Method of producing nipples



Patented May 4, 1937 UNITED STATES PATENT OFFICE 2 Claims.

This invention which relates generally to air relief valves such as areused with steam radiators and the like, is concerned particularly withthe construction of a connecting nipple which is joined to the valvecasing.

A principal object of my invention is to provide for a cylindrical valvecasing a nipple having a flange which may bear against the inner face ofthe casing wall and be secured thereto in any convenient way as bysoldering. A nipple having its flange so disposed is thereby secured ina stronger and more durable manner. The construction of the nippleflange, however, presents numerous difficulties, as it must conform tothe curvature of the cylindrical wall with which it co-operates.According to this invention I form at one end of the nipple a flangewhich is first straight, and then reshape the flange to correspond withthe curvature of the casing wall to which it is connected. By soproceeding I preserve the strength of the nipple and at the same timefacilitate the formation of the flange thereupon. The present inventiontherefore is concerned not merely with the construction of a valvecasing nipple having such a curved flange, but also with the method thatis employed in its manufacture.

A suggestive embodiment of this invention is set forth in theaccompanying drawing, wherein- Figure 1 is a longitudinal sectionthrough an air relief valve having fitted thereto nipple made accordingto this invention;

Fig. 2 is an enlarged transverse section on line 2 of Fig. 1;

Fig. 3 is a longitudinal section through the nipple as it appears whenthe flange is first formed thereon;

Fig. 4 is a similar view showing the flange after it has been curved toflnai position; and

Fig. 5 which is a view similar to Fig. 2 shows the nipple applied to avalve casing having an external effect which forms interiorly of thecasing a seat for the nipple flange.

The valve structure herein shown comprises a cylindrical casing C with adome wherein is an opening to receive a plug P. Through this plugextends an axial bore wherein is formed a valve seat 6. The plug may besecured immovably to the casing as by solder 7.

The opposite casing end may be closed as by means of a base B having amarginal flange H) which closely surrounds the adjacent end of thecasing. This base may be aflixed immovably to the casing as by solderll. Formed in the clearly in Fig. 4.

base is an upstanding boss in the form of a truncated cone I5 having aneck it which is internally threaded to co-operate with the threads of ascrew l! which carries at its upper end a head 18 whose upper face isslightly convex, as shown. Upon the head is supported a float F, hereshown as a sealed container, having upstanding from its upper end a pin20 adapted to enter the bore in the plug. The upper end of the pin mayengage with the valve seat 6 so as to close the opening through the borewhen the float is raised off of its support upon the head 18. Thelowermost position of the float is deter mined by adjustment of thescrew i7 within the threaded neck l6.

Formed in the wall of the valve casing adjacent the base is a roundopening through which is. extended a cylindrical nipple N havingexternal threads 28. At the inner end of this nipple is a flange 27adapted to rest against the inner face of the casing wall. As the valvecasing is cylindrical in form, the flange should be similarly curved inorder to flt squarely thereagainst. I have accordingly so curved theflange, doing this in a way that is advantageous from variousstandpoints.

As best shown in Fig. 3, the nipple threads extend for the major portionof its length. The walls of this nipple, however, are of full thicknessin the region 28 which is adjacent the flange 2i. Extending around thenipple adjacent the base of the flange is a groove 29 which is cut intothe wall at a point where it is of maximum thickness. In an early stage,the flange is straight, i. e., it lies in a single plane, as shown inFig. 3. Thereafter the nipple is put into a shaping die which curves theflange about an axis that intersects that of the nipple (see Fig. l). Inthis operation the groove is widened, and also shallowed, at twoopposite points and is narrowed at two other opposite points about 90therefrom. This is indicated This variation in the width of the grooveresults from the displacement of metal that takes place when the flangeis reshaped to curved form. By reason of the presence of this groove itis possible to produce this curvature with greater facility, the metalof the nipple thereby yielding more easily, as required at certainpoints, to take up its new position.

A nipple having its flange so curved is adapted to be fitted into thevalve casing with the flange resting upon the inner face of its wall.When so fitted it may be secured immovably as by solder connections 36and 3|. A nipple which is so constructed and applied to the valve casingmakes a very strong connection therewith, and will not separate from thecasing in response to a very strong pulling force.

In Fig. 5 I have shown exactly the same construction of nipple andflange except that the valve casing is exteriorly offset as at 35 toprovide a seat which will accommodate the flange of the nipple. All theadvantages which accrue with a construction as hereinbefore describedapply to this type of connection as well, and in addition the interiorof the casing is preserved clear and smooth.

In the manufacture of the present nipple, I prefer to start with a solidbar from which the nipple is turned. It is then annealed. The flange isnext formed in a turning operation and later is shaped by a die. Thisshaping operation may proceed without detriment to the nipple andwithout any impairment of its strength, due to the provision of theannular groove around the nipple which facilitates the displacement ofmetal necessary for the flange to assume the curvature which has beendescribed. Finally, as by the application of solder, the nipple issecurely fixed in place and in a manner which will be leak proof.

I claim:

1. The method of producing a nipple having a curved flange whichcomprises the steps of first forming on the nipple a straight flangewith an annular groove of uniform width adjacent its base and thenshaping the flange into curved form with a concurrent variation of thegroove width.

2. The method of producing a nipple having a curved flange whichcomprises the steps of first forming on the nipple a straight flangewith an annular groove of uniform width adjacent its base, and thenshaping the flange into curved form with a concurrent narrowing of thegroove at diametrically opposite points and a concurrent widening of thegroove at intermediate diametrically opposite points.

FRED W. LEUTHESSERi

